Stretch polyester and acrylic spun yarn

Abstract

The invention provides a spun yarn comprising polyester bicomponent staple fiber and acrylic staple fiber. The invention further provides a method for making spun yarns and fabrics. The spun yarn of the invention comprises at least 30 weight percent acrylic staple fiber and from 17 to 45 weight percent polyester bicomponent staple fiber comprising poly(ethylene terephthalate) and poly(trimethylene terephthalate), based on the total weight of the yarn.

What is claimed is:  
     
         1 . A spun yarn comprising at least about 30 weight percent acrylic staple fiber and from about 17 to 45 weight percent polyester bicomponent staple fiber comprising poly(ethylene terephthalate) and poly(trimethylene terephthalate), based on the total weight of the yarn.  
     
     
         2 . The spun yarn of  claim 1  containing at least about 50 weight percent acrylic staple fiber and from about 25 to about 40 weight percent polyester bicomponent fiber based on the total weight of the yarn.  
     
     
         3 . The spun yarn of  claim 1  having a total boil-off shrinkage of at least about 32% and wherein the acrylic staple fiber is at least 85 percent by weight of acrylonitrile units.  
     
     
         4 . The spun yarn of  claim 1  wherein the bicomponent fiber has a crimp development value of at least about 35% and a crimp index value of from about 10% to about 45%.  
     
     
         5 . The spun yarn of  claim 1  wherein the bicomponent fiber has a crimp index value of from about 20% to about 30%.  
     
     
         6 . A process for making the spun yarn of  claim 1  comprising the steps of: 
 a) providing the bicomponent staple fiber;  
 b) providing the acrylic staple fiber;  
 c) combining by intimate blending the acrylic and the bicomponent staple fibers so that a resulting mixture contains from about 17 weight percent to about 45 weight percent bicomponent staple fiber and at least about 30 weight percent acrylic staple fiber based on the total weight of the yarn;  
 d) carding the blended fibers to form a card sliver;  
 e) drawing the card sliver;  
 f) doubling and redrawing the card sliver;  
 g) converting the drawn sliver to roving; and  
 h) ring-spinning the roving to form the spun yarn.  
 
     
     
         7 . The process of  claim 6  wherein the mixture contains from about 25 weight percent to about 40 weight percent bicomponent staple fiber based on the total weight of the yarn.  
     
     
         8 . The process of  claim 6  wherein the ring-spinning provides a twist multiplier of about 3 to 5.5, the polyester bicomponent staple fiber has a total boil-off shrinkage of at least about 32%, and the acrylic staple fiber is at least 85 percent by weight of acrylonitrile units.  
     
     
         9 . The process of  claim 6  wherein the bicomponent fiber has a crimp index value of at least about 10%, the bicomponent fiber has a crimp index value no higher than about 45%, and the bicomponent fiber has a crimp development value of at least about 35%.  
     
     
         10 . A fabric selected from the group consisting of knits and wovens and comprising a spun yarn made by the process of  claim 6.